THE FLAT-FISH FAMILY 25 I 



the town. The hooks are very small, and the bait used is lug- 

 worms. The fishing is carried on only in summer, the boats 

 used being open cobles. Along the Yorkshire coast a rock)- 

 bottom extends out from the shore seawards for some distance, 

 and only beyond it is sandy ground found in most places, but at 

 Cloughton a narrow strip of sand runs almost to the head of the 

 Wyke, and the soles are attracted to this spot by the large 

 number of marine worms to be obtained there. 



Breeding. — The proportions of the sexes in number and size 

 have not been so carefully ascertained as in the case of other 

 species, but there is no doubt that the females are both more 

 numerous and larger than the males. In the Irish Survey, of 414 

 specimens examined, 245 were females, 169 males, or 144 

 females to 100 males. The smallest mature female was 2 inches 

 longer than the smallest mature male. The very small size of 

 the male sexual organs has already been m.entioned in Part I. 



Off the coast of Devon and Cornwall the spawning season 

 extends from the middle of February to the middle of Ma)-. 

 On the west coast of Ireland ripe females were taken in March, 

 April, May, and June, but principally in March and April. In 

 the North Sea spawning was observed from the end of April to 

 the end of July. A sole of one pound weight has been calcu- 

 lated to contain 1 34,000 eggs. 



Spawning takes place in the deeper water : on the south- 

 west coast of England, outside the Eddy stone, south of the Wolf 

 rock, off the north coast of Cornwall, and in Mount's Bay, at 

 from 20 to 40 fathoms. In the bays and inlets of the west coast 

 of Ireland ripe females were taken between 5 and 15 fathoms, 

 and also between 22 and 53 fathoms. 



The &g^ of the sole when fertilised is buoyant, and floats in 

 sea water: it is 1-47 to r5 i mm. in diameter (yfo to yIjo i'^ch, 

 or ttV inch). It is easily distinguished from the eggs of other 

 fishes in British seas by the facts that the outer layer of the yolk 

 is divided into separate segments, and that there are an immense 

 number of minute oil globules arranged in irregular patches at 

 the surface of the yolk (Fig. 114). 



The larva hatched out on the tenth day at a temperature of 

 48° to 50°. The larva resembles that of other flat fishes, except 

 in the peculiarities of the yolk ; it is 3-5 to 37 mm. long (,-V to fV 

 inch) ; the coloured pigment is orange-}-ellow by reflected light, 



